The objective of this Component is to provide extensive tissue culture support for storage of cell lines, for the large scale culture of individual lines required for protein purification or isolation of cell- specific protein factors, for immortalization of lymphocytes for human genetics studies, and to provide embryonic stem cells and feeder layer cultures for gene targeting studies. This Core will be expanded to support 20% of a senior cardiovascular researcher who will analyze heart function in our transgenic, knockout and gene replacement mice. This will make possible the detailed and quantitative analysis of physiological and pharmacological characteristics of knockout or gene replacement mice, including heart and vascular smooth muscle.